Theora video support + audio improvements (#20)

- `SoundInstance.Play` no longer takes a loop parameter
- `SoundInstance.Stop` is split into `Stop` and `StopImmediate` instead of taking an immediate parameter
- Added `StreamingSoundSeekable` to better support streaming audio that does not support seek
- `StreamingSound` no longer has a Loop property, but `StreamingSoundSeekable` does
- abstract `StreamingSound.AddBuffer` renamed to `FillBuffer`
- `FillBuffer` is now provided with a native buffer to avoid an extra data copy
- `StreamingSound` buffer implementation optimized to avoid repeated alloc/frees

- added `Video` class which can load and play Theora (.ogv) streaming video/audio

Reviewed-on: MoonsideGames/MoonWorks#20

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "lib/WellspringCS"]
 	path = lib/WellspringCS
 	url = https://gitea.moonside.games/MoonsideGames/WellspringCS.git
+[submodule "lib/Theorafile"]
+	path = lib/Theorafile
+	url = https://github.com/FNA-XNA/Theorafile.git

MoonWorks.csproj

@@ -15,6 +15,7 @@
 		<ProjectReference Include=".\lib\RefreshCS\RefreshCS.csproj" />
 		<ProjectReference Include=".\lib\FAudio\csharp\FAudio-CS.Core.csproj" />
 		<ProjectReference Include=".\lib\WellspringCS\WellspringCS.csproj" />
+		<ProjectReference Include=".\lib\Theorafile\csharp\Theorafile-CS.Core.csproj" />
 	</ItemGroup>
 
 	<ItemGroup>
@@ -22,4 +23,13 @@
 			<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
 		</None>
 	</ItemGroup>
+
+	<ItemGroup>
+		<EmbeddedResource Include="src\Video\Shaders\Compiled\FullscreenVert.spv">
+			<LogicalName>MoonWorks.Shaders.FullscreenVert.spv</LogicalName>
+		</EmbeddedResource>
+		<EmbeddedResource Include="src\Video\Shaders\Compiled\YUV2RGBAFrag.spv">
+			<LogicalName>MoonWorks.Shaders.YUV2RGBAFrag.spv</LogicalName>
+		</EmbeddedResource>
+	</ItemGroup>
 </Project>

MoonWorks.dll.config

@@ -15,4 +15,8 @@
 	<dllmap dll="Wellspring" os="windows" target="Wellspring.dll"/>
 	<dllmap dll="Wellspring" os="osx" target="libWellspring.0.dylib"/>
 	<dllmap dll="Wellspring" os="linux,freebsd,netbsd" target="libWellspring.so.0"/>
+
+	<dllmap dll="Theorafile" os="windows" target="libtheorafile.dll"/>
+	<dllmap dll="Theorafile" os="osx" target="libtheorafile.dylib"/>
+	<dllmap dll="Theorafile" os="linux,freebsd,netbsd" target="libtheorafile.so"/>
 </configuration>

lib/Theorafile

@@ -0,0 +1 @@
+Subproject commit dd8c7fa69e678b6182cdaa71458ad08dd31c65da

src/Audio/SoundInstance.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Runtime.InteropServices;
-using MoonWorks.Math.Float;
 
 namespace MoonWorks.Audio
 {
@@ -8,13 +7,12 @@ namespace MoonWorks.Audio
 	{
 		internal IntPtr Handle;
 		internal FAudio.FAudioWaveFormatEx Format;
-		public bool Loop { get; protected set; } = false;
 
 		protected FAudio.F3DAUDIO_DSP_SETTINGS dspSettings;
 
 		public bool Is3D { get; protected set; }
 
-		public abstract SoundState State { get; protected set; }
+		public virtual SoundState State { get; protected set; }
 
 		private float _pan = 0;
 		public float Pan
@@ -238,11 +236,10 @@ namespace MoonWorks.Audio
 			);
 		}
 
-		public abstract void Play(bool loop);
+		public abstract void Play();
 		public abstract void Pause();
-		public abstract void Stop(bool immediate);
+		public abstract void Stop();
-		public abstract void Seek(float seconds);
+		public abstract void StopImmediate();
-		public abstract void Seek(uint sampleFrame);
 
 		private void InitDSPSettings(uint srcChannels)
 		{
@@ -345,8 +342,7 @@ namespace MoonWorks.Audio
 
 		protected override void Destroy()
 		{
-			Stop(true);
+			StopImmediate();
-
 			FAudio.FAudioVoice_DestroyVoice(Handle);
 			Marshal.FreeHGlobal(dspSettings.pMatrixCoefficients);
 		}

src/Audio/StaticSoundInstance.cs

@@ -6,6 +6,8 @@ namespace MoonWorks.Audio
 	{
 		public StaticSound Parent { get; }
 
+		public bool Loop { get; set; }
+
 		private SoundState _state = SoundState.Stopped;
 		public override SoundState State
 		{
@@ -18,7 +20,7 @@ namespace MoonWorks.Audio
 				);
 				if (state.BuffersQueued == 0)
 				{
-					Stop(true);
+					StopImmediate();
 				}
 
 				return _state;
@@ -38,15 +40,13 @@ namespace MoonWorks.Audio
 			Parent = parent;
 		}
 
-		public override void Play(bool loop = false)
+		public override void Play()
 		{
 			if (State == SoundState.Playing)
 			{
 				return;
 			}
 
-			Loop = loop;
-
 			if (Loop)
 			{
 				Parent.Handle.LoopCount = 255;
@@ -79,21 +79,20 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		public override void Stop(bool immediate = true)
+		public override void Stop()
 		{
-			if (immediate)
+			FAudio.FAudioSourceVoice_ExitLoop(Handle, 0);
+			State = SoundState.Stopped;
+		}
+
+		public override void StopImmediate()
 		{
 			FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
 			FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
 			State = SoundState.Stopped;
 		}
-			else
-			{
-				FAudio.FAudioSourceVoice_ExitLoop(Handle, 0);
-			}
-		}
 
-		private void PerformSeek(uint sampleFrame)
+		public void Seek(uint sampleFrame)
 		{
 			if (State == SoundState.Playing)
 			{
@@ -102,20 +101,6 @@ namespace MoonWorks.Audio
 			}
 
 			Parent.Handle.PlayBegin = sampleFrame;
-			Play();
-		}
-
-		public override void Seek(float seconds)
-		{
-			uint sampleFrame =
-				(uint) (Parent.SamplesPerSecond * seconds);
-
-			PerformSeek(sampleFrame);
-		}
-
-		public override void Seek(uint sampleFrame)
-		{
-			PerformSeek(sampleFrame);
 		}
 
 		public void Free()

src/Audio/StreamingSound.cs

@@ -1,38 +1,46 @@
 using System;
-using System.Collections.Generic;
 using System.Runtime.InteropServices;
 
 namespace MoonWorks.Audio
 {
 	/// <summary>
 	/// For streaming long playback.
-	/// Can be extended to support custom decoders.
+	/// Must be extended with a decoder routine called by FillBuffer.
+	/// See StreamingSoundOgg for an example.
 	/// </summary>
 	public abstract class StreamingSound : SoundInstance
 	{
-		private readonly List<IntPtr> queuedBuffers = new List<IntPtr>();
+		private const int BUFFER_COUNT = 3;
-		private readonly List<uint> queuedSizes = new List<uint>();
+		private readonly IntPtr[] buffers;
-		private const int MINIMUM_BUFFER_CHECK = 3;
+		private int nextBufferIndex = 0;
+		private uint queuedBufferCount = 0;
+		protected abstract int BUFFER_SIZE { get; }
 
-		public int PendingBufferCount => queuedBuffers.Count;
+		public unsafe StreamingSound(
-
-		public StreamingSound(
 			AudioDevice device,
 			ushort formatTag,
 			ushort bitsPerSample,
 			ushort blockAlign,
 			ushort channels,
 			uint samplesPerSecond
-		) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond) { }
+		) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond)
+		{
+			device.AddDynamicSoundInstance(this);
 
-		public override void Play(bool loop = false)
+			buffers = new IntPtr[BUFFER_COUNT];
+			for (int i = 0; i < BUFFER_COUNT; i += 1)
+			{
+				buffers[i] = (IntPtr) NativeMemory.Alloc((nuint) BUFFER_SIZE);
+			}
+		}
+
+		public override void Play()
 		{
 			if (State == SoundState.Playing)
 			{
 				return;
 			}
 
-			Loop = loop;
 			State = SoundState.Playing;
 
 			Update();
@@ -48,19 +56,21 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		public override void Stop(bool immediate = true)
+		public override void Stop()
 		{
-			if (immediate)
+			State = SoundState.Stopped;
+		}
+
+		public override void StopImmediate()
 		{
 			FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
 			FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
 			ClearBuffers();
-			}
 
 			State = SoundState.Stopped;
 		}
 
-		internal void Update()
+		internal unsafe void Update()
 		{
 			if (State != SoundState.Playing)
 			{
@@ -73,68 +83,45 @@ namespace MoonWorks.Audio
 				FAudio.FAUDIO_VOICE_NOSAMPLESPLAYED
 			);
 
-			while (PendingBufferCount > state.BuffersQueued)
+			queuedBufferCount = state.BuffersQueued;
-				lock (queuedBuffers)
-				{
-					Marshal.FreeHGlobal(queuedBuffers[0]);
-					queuedBuffers.RemoveAt(0);
-				}
 
 			QueueBuffers();
 		}
 
 		protected void QueueBuffers()
 		{
-			for (
+			for (int i = 0; i < BUFFER_COUNT - queuedBufferCount; i += 1)
-				int i = MINIMUM_BUFFER_CHECK - PendingBufferCount;
-				i > 0;
-				i -= 1
-			)
 			{
 				AddBuffer();
 			}
 		}
 
-		protected void ClearBuffers()
+		protected unsafe void ClearBuffers()
 		{
-			lock (queuedBuffers)
+			nextBufferIndex = 0;
-			{
+			queuedBufferCount = 0;
-				foreach (IntPtr buf in queuedBuffers)
-				{
-					Marshal.FreeHGlobal(buf);
-				}
-				queuedBuffers.Clear();
-				queuedSizes.Clear();
-			}
 		}
 
-		protected void AddBuffer()
+		protected unsafe void AddBuffer()
 		{
-			AddBuffer(
+			var buffer = buffers[nextBufferIndex];
-				out var buffer,
+			nextBufferIndex = (nextBufferIndex + 1) % BUFFER_COUNT;
-				out var bufferOffset,
+
-				out var bufferLength,
+			FillBuffer(
-				out var reachedEnd
+				(void*) buffer,
+				BUFFER_SIZE,
+				out int filledLengthInBytes,
+				out bool reachedEnd
 			);
 
-			var lengthInBytes = bufferLength * sizeof(float);
-
-			IntPtr next = Marshal.AllocHGlobal((int) lengthInBytes);
-			Marshal.Copy(buffer, (int) bufferOffset, next, (int) bufferLength);
-
-			lock (queuedBuffers)
-			{
-				queuedBuffers.Add(next);
-				if (State != SoundState.Stopped)
-				{
 			FAudio.FAudioBuffer buf = new FAudio.FAudioBuffer
 			{
-						AudioBytes = lengthInBytes,
+				AudioBytes = (uint) filledLengthInBytes,
-						pAudioData = next,
+				pAudioData = (IntPtr) buffer,
 				PlayLength = (
-							lengthInBytes /
+					(uint) (filledLengthInBytes /
 					Format.nChannels /
-							(uint) (Format.wBitsPerSample / 8)
+					(uint) (Format.wBitsPerSample / 8))
 				)
 			};
 
@@ -143,39 +130,36 @@ namespace MoonWorks.Audio
 				ref buf,
 				IntPtr.Zero
 			);
-				}
+
-				else
+			queuedBufferCount += 1;
-				{
-					queuedSizes.Add(lengthInBytes);
-				}
-			}
 
 			/* We have reached the end of the file, what do we do? */
 			if (reachedEnd)
 			{
-				if (Loop)
+				OnReachedEnd();
-				{
-					SeekStart();
-				}
-				else
-				{
-					Stop(false);
-				}
 			}
 		}
 
-		protected abstract void AddBuffer(
+		protected virtual void OnReachedEnd()
-			out float[] buffer,
+		{
-			out uint bufferOffset, /* in floats */
+			Stop();
-			out uint bufferLength, /* in floats */
+		}
+
+		protected unsafe abstract void FillBuffer(
+			void* buffer,
+			int bufferLengthInBytes, /* in bytes */
+			out int filledLengthInBytes, /* in bytes */
 			out bool reachedEnd
 		);
 
-		protected abstract void SeekStart();
+		protected unsafe override void Destroy()
-
-		protected override void Destroy()
 		{
-			Stop(true);
+			StopImmediate();
+
+			for (int i = 0; i < BUFFER_COUNT; i += 1)
+			{
+				NativeMemory.Free((void*) buffers[i]);
+			}
 		}
 	}
 }

src/Audio/StreamingSoundOgg.cs

@@ -4,28 +4,23 @@ using System.Runtime.InteropServices;
 
 namespace MoonWorks.Audio
 {
-	public class StreamingSoundOgg : StreamingSound
+	public class StreamingSoundOgg : StreamingSoundSeekable
 	{
-		// FIXME: what should this value be?
-		public const int BUFFER_SIZE = 1024 * 128;
-
 		private IntPtr VorbisHandle;
 		private IntPtr FileDataPtr;
 		private FAudio.stb_vorbis_info Info;
 
-		private readonly float[] buffer; // currently decoded bytes
+		protected override int BUFFER_SIZE => 32768;
 
-		public override SoundState State { get; protected set; }
+		public unsafe static StreamingSoundOgg Load(AudioDevice device, string filePath)
-
-		public static StreamingSoundOgg Load(AudioDevice device, string filePath)
 		{
 			var fileData = File.ReadAllBytes(filePath);
-			var fileDataPtr = Marshal.AllocHGlobal(fileData.Length);
+			var fileDataPtr = NativeMemory.Alloc((nuint) fileData.Length);
-			Marshal.Copy(fileData, 0, fileDataPtr, fileData.Length);
+			Marshal.Copy(fileData, 0, (IntPtr) fileDataPtr, fileData.Length);
-			var vorbisHandle = FAudio.stb_vorbis_open_memory(fileDataPtr, fileData.Length, out int error, IntPtr.Zero);
+			var vorbisHandle = FAudio.stb_vorbis_open_memory((IntPtr) fileDataPtr, fileData.Length, out int error, IntPtr.Zero);
 			if (error != 0)
 			{
-				((GCHandle) fileDataPtr).Free();
+				NativeMemory.Free(fileDataPtr);
 				Logger.LogError("Error opening OGG file!");
 				Logger.LogError("Error: " + error);
 				throw new AudioLoadException("Error opening OGG file!");
@@ -34,7 +29,7 @@ namespace MoonWorks.Audio
 
 			return new StreamingSoundOgg(
 				device,
-				fileDataPtr,
+				(IntPtr) fileDataPtr,
 				vorbisHandle,
 				info
 			);
@@ -42,7 +37,7 @@ namespace MoonWorks.Audio
 
 		internal StreamingSoundOgg(
 			AudioDevice device,
-			IntPtr fileDataPtr, // MUST BE AN ALLOCHGLOBAL HANDLE!!
+			IntPtr fileDataPtr, // MUST BE A NATIVE MEMORY HANDLE!!
 			IntPtr vorbisHandle,
 			FAudio.stb_vorbis_info info
 		) : base(
@@ -57,12 +52,9 @@ namespace MoonWorks.Audio
 			FileDataPtr = fileDataPtr;
 			VorbisHandle = vorbisHandle;
 			Info = info;
-			buffer = new float[BUFFER_SIZE];
-
-			device.AddDynamicSoundInstance(this);
 		}
 
-		private void PerformSeek(uint sampleFrame)
+		public override void Seek(uint sampleFrame)
 		{
 			if (State == SoundState.Playing)
 			{
@@ -80,49 +72,32 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		public override void Seek(float seconds)
+		protected unsafe override void FillBuffer(
-		{
+			void* buffer,
-			uint sampleFrame = (uint) (Info.sample_rate * seconds);
+			int bufferLengthInBytes,
-			PerformSeek(sampleFrame);
+			out int filledLengthInBytes,
-		}
-
-		public override void Seek(uint sampleFrame)
-		{
-			PerformSeek(sampleFrame);
-		}
-
-		protected override void AddBuffer(
-			out float[] buffer,
-			out uint bufferOffset,
-			out uint bufferLength,
 			out bool reachedEnd
 		)
 		{
-			buffer = this.buffer;
+			var lengthInFloats = bufferLengthInBytes / sizeof(float);
 
 			/* NOTE: this function returns samples per channel, not total samples */
 			var samples = FAudio.stb_vorbis_get_samples_float_interleaved(
 				VorbisHandle,
 				Info.channels,
-				buffer,
+				(IntPtr) buffer,
-				buffer.Length
+				lengthInFloats
 			);
 
 			var sampleCount = samples * Info.channels;
-			bufferOffset = 0;
+			reachedEnd = sampleCount < lengthInFloats;
-			bufferLength = (uint) sampleCount;
+			filledLengthInBytes = sampleCount * sizeof(float);
-			reachedEnd = sampleCount < buffer.Length;
 		}
 
-		protected override void SeekStart()
+		protected unsafe override void Destroy()
-		{
-			FAudio.stb_vorbis_seek_start(VorbisHandle);
-		}
-
-		protected override void Destroy()
 		{
 			FAudio.stb_vorbis_close(VorbisHandle);
-			Marshal.FreeHGlobal(FileDataPtr);
+			NativeMemory.Free((void*) FileDataPtr);
 		}
 	}
 }

src/Audio/StreamingSoundSeekable.cs

@@ -0,0 +1,25 @@
+namespace MoonWorks.Audio
+{
+	public abstract class StreamingSoundSeekable : StreamingSound
+	{
+		public bool Loop { get; set; }
+
+		protected StreamingSoundSeekable(AudioDevice device, ushort formatTag, ushort bitsPerSample, ushort blockAlign, ushort channels, uint samplesPerSecond) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond)
+		{
+		}
+
+		public abstract void Seek(uint sampleFrame);
+
+		protected override void OnReachedEnd()
+		{
+			if (Loop)
+			{
+				Seek(0);
+			}
+			else
+			{
+				Stop();
+			}
+		}
+	}
+}

src/Graphics/CommandBuffer.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Runtime.InteropServices;
-using MoonWorks.Math;
 using RefreshCS;
 
 namespace MoonWorks.Graphics
@@ -835,6 +833,26 @@ namespace MoonWorks.Graphics
 			SetTextureData(new TextureSlice(texture), dataPtr, dataLengthInBytes);
 		}
 
+		/// <summary>
+		/// Asynchronously copies YUV data into three textures. Use with compressed video.
+		/// </summary>
+		public void SetTextureDataYUV(Texture yTexture, Texture uTexture, Texture vTexture, IntPtr dataPtr, uint dataLengthInBytes)
+		{
+			Refresh.Refresh_SetTextureDataYUV(
+				Device.Handle,
+				Handle,
+				yTexture.Handle,
+				uTexture.Handle,
+				vTexture.Handle,
+				yTexture.Width,
+				yTexture.Height,
+				uTexture.Width,
+				uTexture.Height,
+				dataPtr,
+				dataLengthInBytes
+			);
+		}
+
 		/// <summary>
 		/// Performs an asynchronous texture-to-texture copy on the GPU.
 		/// </summary>

src/Graphics/GraphicsDevice.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using RefreshCS;
 
 namespace MoonWorks.Graphics
@@ -8,6 +9,11 @@ namespace MoonWorks.Graphics
 	{
 		public IntPtr Handle { get; }
 
+		// Built-in video pipeline
+		private ShaderModule VideoVertexShader { get; }
+		private ShaderModule VideoFragmentShader { get; }
+		internal GraphicsPipeline VideoPipeline { get; }
+
 		public bool IsDisposed { get; private set; }
 
 		private readonly List<WeakReference<GraphicsResource>> resources = new List<WeakReference<GraphicsResource>>();
@@ -28,6 +34,26 @@ namespace MoonWorks.Graphics
 				presentationParameters,
 				Conversions.BoolToByte(debugMode)
 			);
+
+			VideoVertexShader = new ShaderModule(this, GetEmbeddedResource("MoonWorks.Shaders.FullscreenVert.spv"));
+			VideoFragmentShader = new ShaderModule(this, GetEmbeddedResource("MoonWorks.Shaders.YUV2RGBAFrag.spv"));
+
+			VideoPipeline = new GraphicsPipeline(
+				this,
+				new GraphicsPipelineCreateInfo
+				{
+					AttachmentInfo = new GraphicsPipelineAttachmentInfo(
+						new ColorAttachmentDescription(TextureFormat.R8G8B8A8, ColorAttachmentBlendState.None)
+					),
+					DepthStencilState = DepthStencilState.Disable,
+					VertexShaderInfo = GraphicsShaderInfo.Create(VideoVertexShader, "main", 0),
+					FragmentShaderInfo = GraphicsShaderInfo.Create(VideoFragmentShader, "main", 3),
+					VertexInputState = VertexInputState.Empty,
+					RasterizerState = RasterizerState.CCW_CullNone,
+					PrimitiveType = PrimitiveType.TriangleList,
+					MultisampleState = MultisampleState.None
+				}
+			);
 		}
 
 		public CommandBuffer AcquireCommandBuffer()
@@ -77,6 +103,11 @@ namespace MoonWorks.Graphics
 			}
 		}
 
+		private static Stream GetEmbeddedResource(string name)
+		{
+			return typeof(GraphicsDevice).Assembly.GetManifestResourceStream(name);
+		}
+
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!IsDisposed)

src/Input/Gamepad.cs

@@ -159,6 +159,12 @@ namespace MoonWorks.Input
 				{ AxisButtonCode.RightY_Down, RightYDown }
 			};
 
+			TriggerCodeToTriggerButton = new Dictionary<TriggerCode, TriggerButton>
+			{
+				{ TriggerCode.Left, TriggerLeftButton },
+				{ TriggerCode.Right, TriggerRightButton }
+			};
+
 			VirtualButtons = new VirtualButton[]
 			{
 				A,

src/MoonWorksDllMap.cs

@@ -196,6 +196,7 @@ namespace MoonWorks
 			NativeLibrary.SetDllImportResolver(typeof(RefreshCS.Refresh).Assembly, MapAndLoad);
 			NativeLibrary.SetDllImportResolver(typeof(FAudio).Assembly, MapAndLoad);
 			NativeLibrary.SetDllImportResolver(typeof(WellspringCS.Wellspring).Assembly, MapAndLoad);
+			NativeLibrary.SetDllImportResolver(typeof(Theorafile).Assembly, MapAndLoad);
 		}
 
 		#endregion

src/Video/Shaders/Source/Fullscreen.vert

@@ -0,0 +1,9 @@
+#version 450
+
+layout(location = 0) out vec2 outTexCoord;
+
+void main()
+{
+	outTexCoord = vec2((gl_VertexIndex << 1) & 2, gl_VertexIndex & 2);
+	gl_Position = vec4(outTexCoord * 2.0 - 1.0, 0.0, 1.0);
+}

src/Video/Shaders/Source/YUV2RGBA.frag

@@ -0,0 +1,38 @@
+/*
+ * This effect is based on the YUV-to-RGBA GLSL shader found in SDL.
+ * Thus, it also released under the zlib license:
+ * http://libsdl.org/license.php
+ */
+#version 450
+
+layout(location = 0) in vec2 TexCoord;
+
+layout(location = 0) out vec4 FragColor;
+
+layout(binding = 0, set = 1) uniform sampler2D YSampler;
+layout(binding = 1, set = 1) uniform sampler2D USampler;
+layout(binding = 2, set = 1) uniform sampler2D VSampler;
+
+/* More info about colorspace conversion:
+ * http://www.equasys.de/colorconversion.html
+ * http://www.equasys.de/colorformat.html
+ */
+
+const vec3 offset = vec3(-0.0625, -0.5, -0.5);
+const vec3 Rcoeff = vec3(1.164,  0.000,  1.793);
+const vec3 Gcoeff = vec3(1.164, -0.213, -0.533);
+const vec3 Bcoeff = vec3(1.164,  2.112,  0.000);
+
+void main()
+{
+	vec3 yuv;
+	yuv.x = texture(YSampler, TexCoord).r;
+	yuv.y = texture(USampler, TexCoord).r;
+	yuv.z = texture(VSampler, TexCoord).r;
+	yuv += offset;
+
+	FragColor.r = dot(yuv, Rcoeff);
+	FragColor.g = dot(yuv, Gcoeff);
+	FragColor.b = dot(yuv, Bcoeff);
+	FragColor.a = 1.0;
+}

src/Video/StreamingSoundTheora.cs

@@ -0,0 +1,45 @@
+using System;
+using MoonWorks.Audio;
+
+namespace MoonWorks.Video
+{
+	public unsafe class StreamingSoundTheora : StreamingSound
+	{
+		private IntPtr VideoHandle;
+		protected override int BUFFER_SIZE => 8192;
+
+		internal StreamingSoundTheora(
+			AudioDevice device,
+			IntPtr videoHandle,
+			int channels,
+			uint sampleRate
+		) : base(
+			device,
+			3, /* float type */
+			32, /* size of float */
+			(ushort) (4 * channels),
+			(ushort) channels,
+			sampleRate
+		) {
+			VideoHandle = videoHandle;
+		}
+
+		protected override unsafe void FillBuffer(
+			void* buffer,
+			int bufferLengthInBytes,
+			out int filledLengthInBytes,
+			out bool reachedEnd
+		) {
+			var lengthInFloats = bufferLengthInBytes / sizeof(float);
+
+			int samples = Theorafile.tf_readaudio(
+				VideoHandle,
+				(IntPtr) buffer,
+				lengthInFloats
+			);
+
+			filledLengthInBytes = samples * sizeof(float);
+			reachedEnd = Theorafile.tf_eos(VideoHandle) == 1;
+		}
+	}
+}

src/Video/Video.cs

@@ -0,0 +1,357 @@
+/* Heavily based on https://github.com/FNA-XNA/FNA/blob/master/src/Media/Xiph/VideoPlayer.cs */
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using MoonWorks.Audio;
+using MoonWorks.Graphics;
+
+namespace MoonWorks.Video
+{
+	public enum VideoState
+	{
+		Playing,
+		Paused,
+		Stopped
+	}
+
+	public unsafe class Video : IDisposable
+	{
+		internal IntPtr Handle;
+
+		public bool Loop { get; private set; }
+		public float Volume {
+			get => volume;
+			set
+			{
+				volume = value;
+				if (audioStream != null)
+				{
+					audioStream.Volume = value;
+				}
+			}
+		}
+		public float PlaybackSpeed { get; set; }
+		public double FramesPerSecond => fps;
+		private VideoState State = VideoState.Stopped;
+
+		private double fps;
+		private int yWidth;
+		private int yHeight;
+		private int uvWidth;
+		private int uvHeight;
+
+		private void* yuvData = null;
+		private int yuvDataLength;
+		private int currentFrame;
+
+		private GraphicsDevice GraphicsDevice;
+		private Texture RenderTexture = null;
+		private Texture yTexture = null;
+		private Texture uTexture = null;
+		private Texture vTexture = null;
+		private Sampler LinearSampler;
+
+		private AudioDevice AudioDevice = null;
+		private StreamingSoundTheora audioStream = null;
+		private float volume = 1.0f;
+
+		private Stopwatch timer;
+		private double lastTimestamp;
+		private double timeElapsed;
+
+		private bool disposed;
+
+		/* TODO: is there some way for us to load the data into memory? */
+		public Video(GraphicsDevice graphicsDevice, AudioDevice audioDevice, string filename)
+		{
+			GraphicsDevice = graphicsDevice;
+			AudioDevice = audioDevice;
+
+			if (!System.IO.File.Exists(filename))
+			{
+				throw new ArgumentException("Video file not found!");
+			}
+
+			if (Theorafile.tf_fopen(filename, out Handle) < 0)
+			{
+				throw new ArgumentException("Invalid video file!");
+			}
+
+			Theorafile.th_pixel_fmt format;
+			Theorafile.tf_videoinfo(
+				Handle,
+				out yWidth,
+				out yHeight,
+				out fps,
+				out format
+			);
+
+			if (format == Theorafile.th_pixel_fmt.TH_PF_420)
+			{
+				uvWidth = yWidth / 2;
+				uvHeight = yHeight / 2;
+			}
+			else if (format == Theorafile.th_pixel_fmt.TH_PF_422)
+			{
+				uvWidth = yWidth / 2;
+				uvHeight = yHeight;
+			}
+			else if (format == Theorafile.th_pixel_fmt.TH_PF_444)
+			{
+				uvWidth = yWidth;
+				uvHeight = yHeight;
+			}
+			else
+			{
+				throw new NotSupportedException("Unrecognized YUV format!");
+			}
+
+			yuvDataLength = (
+				(yWidth * yHeight) +
+				(uvWidth * uvHeight * 2)
+			);
+
+			yuvData = NativeMemory.Alloc((nuint) yuvDataLength);
+
+			InitializeTheoraStream();
+
+			if (Theorafile.tf_hasvideo(Handle) == 1)
+			{
+				RenderTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) yWidth,
+					(uint) yHeight,
+					TextureFormat.R8G8B8A8,
+					TextureUsageFlags.ColorTarget | TextureUsageFlags.Sampler
+				);
+
+				yTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) yWidth,
+					(uint) yHeight,
+					TextureFormat.R8,
+					TextureUsageFlags.Sampler
+				);
+
+				uTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) uvWidth,
+					(uint) uvHeight,
+					TextureFormat.R8,
+					TextureUsageFlags.Sampler
+				);
+
+				vTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) uvWidth,
+					(uint) uvHeight,
+					TextureFormat.R8,
+					TextureUsageFlags.Sampler
+				);
+
+				LinearSampler = new Sampler(GraphicsDevice, SamplerCreateInfo.LinearClamp);
+			}
+
+			timer = new Stopwatch();
+		}
+
+		public void Play(bool loop = false)
+		{
+			if (State == VideoState.Playing)
+			{
+				return;
+			}
+
+			Loop = loop;
+			timer.Start();
+
+			if (audioStream != null)
+			{
+				audioStream.Play();
+			}
+
+			State = VideoState.Playing;
+		}
+
+		public void Pause()
+		{
+			if (State != VideoState.Playing)
+			{
+				return;
+			}
+
+			timer.Stop();
+
+			if (audioStream != null)
+			{
+				audioStream.Pause();
+			}
+
+			State = VideoState.Paused;
+		}
+
+		public void Stop()
+		{
+			if (State == VideoState.Stopped)
+			{
+				return;
+			}
+
+			timer.Stop();
+			timer.Reset();
+
+			Theorafile.tf_reset(Handle);
+			lastTimestamp = 0;
+			timeElapsed = 0;
+
+			if (audioStream != null)
+			{
+				audioStream.StopImmediate();
+				audioStream.Dispose();
+				audioStream = null;
+			}
+
+			State = VideoState.Stopped;
+		}
+
+		public Texture GetTexture()
+		{
+			if (RenderTexture == null)
+			{
+				throw new InvalidOperationException();
+			}
+
+			if (State == VideoState.Stopped)
+			{
+				return RenderTexture;
+			}
+
+			timeElapsed += (timer.Elapsed.TotalMilliseconds - lastTimestamp) * PlaybackSpeed;
+			lastTimestamp = timer.Elapsed.TotalMilliseconds;
+
+			int thisFrame = ((int) (timeElapsed / (1000.0 / FramesPerSecond)));
+			if (thisFrame > currentFrame)
+			{
+				if (Theorafile.tf_readvideo(
+					Handle,
+					(IntPtr) yuvData,
+					thisFrame - currentFrame
+				) == 1 || currentFrame == -1) {
+					UpdateTexture();
+				}
+
+				currentFrame = thisFrame;
+			}
+
+			bool ended = Theorafile.tf_eos(Handle) == 1;
+			if (ended)
+			{
+				timer.Stop();
+				timer.Reset();
+
+				if (audioStream != null)
+				{
+					audioStream.Stop();
+					audioStream.Dispose();
+					audioStream = null;
+				}
+
+				Theorafile.tf_reset(Handle);
+
+				if (Loop)
+				{
+					// Start over!
+					InitializeTheoraStream();
+
+					timer.Start();
+				}
+				else
+				{
+					State = VideoState.Stopped;
+				}
+			}
+
+			return RenderTexture;
+		}
+
+		private void UpdateTexture()
+		{
+			var commandBuffer = GraphicsDevice.AcquireCommandBuffer();
+
+			commandBuffer.SetTextureDataYUV(
+				yTexture,
+				uTexture,
+				vTexture,
+				(IntPtr) yuvData,
+				(uint) yuvDataLength
+			);
+
+			commandBuffer.BeginRenderPass(
+				new ColorAttachmentInfo(RenderTexture, Color.Black)
+			);
+
+			commandBuffer.BindGraphicsPipeline(GraphicsDevice.VideoPipeline);
+			commandBuffer.BindFragmentSamplers(
+				new TextureSamplerBinding(yTexture, LinearSampler),
+				new TextureSamplerBinding(uTexture, LinearSampler),
+				new TextureSamplerBinding(vTexture, LinearSampler)
+			);
+
+			commandBuffer.DrawPrimitives(0, 1, 0, 0);
+
+			commandBuffer.EndRenderPass();
+
+			GraphicsDevice.Submit(commandBuffer);
+		}
+
+		private void InitializeTheoraStream()
+		{
+			// Grab the first video frame ASAP.
+			while (Theorafile.tf_readvideo(Handle, (IntPtr) yuvData, 1) == 0);
+
+			// Grab the first bit of audio. We're trying to start the decoding ASAP.
+			if (AudioDevice != null && Theorafile.tf_hasaudio(Handle) == 1)
+			{
+				int channels, sampleRate;
+				Theorafile.tf_audioinfo(Handle, out channels, out sampleRate);
+				audioStream = new StreamingSoundTheora(AudioDevice, Handle, channels, (uint) sampleRate);
+			}
+
+			currentFrame = -1;
+		}
+
+		protected virtual void Dispose(bool disposing)
+		{
+			if (!disposed)
+			{
+				if (disposing)
+				{
+					// dispose managed state (managed objects)
+					RenderTexture.Dispose();
+					yTexture.Dispose();
+					uTexture.Dispose();
+					vTexture.Dispose();
+				}
+
+				// free unmanaged resources (unmanaged objects)
+				Theorafile.tf_close(ref Handle);
+				NativeMemory.Free(yuvData);
+
+				disposed = true;
+			}
+		}
+
+		~Video()
+		{
+		    // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+		    Dispose(disposing: false);
+		}
+
+		public void Dispose()
+		{
+			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+			Dispose(disposing: true);
+			GC.SuppressFinalize(this);
+		}
+	}
+}